1. Field of the Invention
The present invention relates generally to imaging a person's eye and more specifically to imaging the anterior segment including the cornea, lens and anterior chamber of the eye, the posterior segment of the eye including the ocular fundus for imaging modalities such as color fundus, fluorescein angiography, ICG angiography, red-free, blue, red, near infrared, infrared, various types of auto-fluorescence at various wavelengths, and functional imaging such as flavoprotein auto-fluorescence and other fluorophores including those in the retinoid cycle.
2. Description of Related Art
Many comprehensive ophthalmologists and optometrists fail to fully utilize ophthalmic imaging devices (either traditional fundus cameras or imaging at the slit lamp) for a variety of reasons such as present day devices are expensive, image quality is poor, devices are difficult to align to a patient's eye, staff is not properly trained, images are not easily accessed, and overall device performance does not allow clinicians to realize the benefits and value of imaging. While physicians would always prefer a widely dilated pupil for retinal examination, this is not always possible or convenient for patients. Problems managing ghost and other reflections during examination, with undilated or dilated pupils, and lack of patient cooperation are common.
Adoption of retinal imaging devices (fundus cameras) historically has been largely in retina subspecialty where experienced technicians have been trained to operate complex equipment. While there has been some market expansion to general ophthalmology and optometry of non-mydriatic fundus cameras, device expense, ease of access, and complexity of operation have hindered the widespread adoption of current devices. Often these are separate free-standing devices that take up additional office space and are not convenient to the examination lane where primary eye exams are performed. Although many practices place existing devices in patient test areas, they are not highly utilized for all the reasons previously stated. Current slit lamp imaging systems are difficult to operate and do not eliminate specular reflections or other reflections from images. Additionally, lighting is not easily controlled and is sub-optimal for retinal imaging over a wide field. Fundus cameras employ an annulus to illuminate the retina and therefore require a larger pupil size to obtain images. These devices can be difficult to align to a patient's pupil.
Additionally, some systems today utilize a point source for illumination, but their field-of-view of the retina is severely limited, optical artifacts are often present, can be difficult to eliminate, and image quality is generally poor. Other systems use scanning laser systems which are expensive, and do not offer color imaging modes. Some scanning laser systems also suffer from central artifacts and other reflections. Scanning laser systems have been typically targeted at retina specialty due to specialized diagnostic functionality (fluorescein angiography, ICG Angiography and Auto-fluorescence).
With an aging population and significantly increased prevalence of eye disease, there is a large unmet need for cost-effective retinal imaging for the mass markets of ophthalmology and optometry that has automated features, is capable of imaging through small pupils, is easy to operate, and offers good image quality with artifact-free images.